1. Field of the Invention
The National Aeronautics and Space Administration is involved in the development of large structures that may be either assembled in space or deployed after launch into space.
This invention relates to such a large structure as a deployable and restowable parabolic antennae for use in space to Earth and other communications systems.
2. Description of Prior Art
The concept of deployable and restowable large diameter, hoop-column mesh-type antennae for use in space is broadly known.
The desirability of providing this type of hoop-column mesh antenna with manual means for adjusting the contour of the antenna to a selected three-dimensional contour is also known.
The conventional manual method and apparatus for selectively adjusting the individual hoop and surface cords to accomplish this adjustment has been performed on Earth and found to be tedious and time-consuming, requiring up to eight hours to perform. Further such adjustment is limited to a deployed surface accuracy of approximately 0.01 inch. Such a deployment and adjustment in space would likely take far longer with less accuracy in providing the desired and critical antenna surface contour for use in space communications systems.
An object of the invention is to provide a control system for automatically adjusting the lengths of a plurality of control cords to control the surface contour of a hoop-column type antenna.
A further object of the invention is to provide a plurality of actuator assemblies mounted on said antenna to selectively and individually or simultaneously adjust the lengths of said plurality of control cords to control the surface contour of said antenna.
Still another object is to provide command signal means for controlling said actuator assemblies.